Field of the Invention
The invention relates to a method for operating a current sense amplifier having a latch configuration. A supply voltage is applied to the latch configuration. Transistors of the latch configuration are connected to one another via nodes and are connected to precharge transistors. The current sense amplifier has sense transistors which are connected downstream of an input and are provided between the latch configuration and an output stage. The precharge transistors are provided between the input and the supply voltage and are controlled via the nodes.
Such a current sense amplifier is conventional and has been in widespread use for a long time. The signal-to-noise ratio of such a current sense amplifier is in many cases still unsatisfactory which can be attributed to technological problems during the production of the current sense amplifier.
Specifically, as a result of technological process fluctuations, the nodes in the current sense amplifier may have different capacitances. This means that the nodes can discharge themselves even when identical voltages are present at them. This parasitic discharging process is dependent on the gate voltage applied to the sense transistors. In other words, there are voltage ranges in which the signal-to-noise ratio of the current sense amplifier drifts into unsatisfactory ranges.
In-order to overcome these difficulties, a relatively long waiting time has been used in the past to ensure that the signals applied to the gates of the sense transistors have been built up or developed sufficiently before actually switching the current sense amplifier on. It has also been suggested to use slower operating sense concepts. However, these approaches have been found to be cumbersome.